2nd ICAI 2022

International Conference on Automotive Industry 2022

Mladá Boleslav, Czech Republic

cycles was preceded by driving on a highway for 40 minutes. Passenger space heating was off during the charging. The charging was done using a DC charging station with a max. output power of 50 kW, which is the predominant type in the Czech Republic. Table 7: Direct current recharging (average from all charging cycles) Charging cycle no. 1 2 3 Ambient temperature [°C] 0.5 2.0 3.0 Initial battery temperature [°C] 15 22 27 Battery temperature upon charging completion [°C] 22 28 30 Maximum charging power when charging [kW] 50.7 50.6 51.7 Minimum charging power when charging [kW] 24 24 24 Average charging power [kW] 35 39 43 Utilization of available charging power by the vehicle [%] 70 79 85 Initial SOC of traction battery [%] 53.5 55 55.5 SOC of traction battery upon charging completion [%] 80.0 79.6 79.6 Energy charged (from the screen of the charging station) [kWh] 22.2 20.7 19.8 Energy consumed by the trip (data from the OBD diag. plug) [kWh] 17.9 16.9 16.5 Charging efficiency [%] 80.6 81.6 83.3 Charging time [hh:mm] 00:38 00:31 00:27 Source: Research data The charging efficiency is calculated as a ratio of the energy consumed in the previous trip to the energy taken from the charging point during the subsequent charging. The measurement data show that battery temperature affects the charging time (38 versus 27 minutes) and charging efficiency (80 to 83 %). We can see that the efficiency of DC charging compared to AC charging, which is done at lower rate, is significantly worse (about 81% for DC compared to the 90% of AC charging). 6. Conclusion From the standpoint of electrical energy consumption, the measurement has shown that highway sections are the most energy-demanding route types in the Czech conditions. This is primarily due to the highest driving speed. On the other hand, the consumption of energy of BEV, compared to summer (exterior temperature 22 to 30 °C), increase during winter (exterior temperature about 0 °C), and the most significant changes are observed in the hill/mountain-like routes.

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